Charles hugh duffy



0 1'. DUFFY, FBK ma. max-amen man MAR. .13, 1920.

I Reissued Apr. 27, 16929a UNITED STATES PATENT oFFIo.

CHARLES HUGH DUFFY, OF. CHEVY CHASE, MIARYLAND;

SPARK-PLUG.

Specification of Reissued Letters Patent. fieissugfl Apr, 2;"5, 192%,, Original No. 1,260,884, dated March 26, 1918, Serial No. 183,549, filed. July 30, 1912.

Application for reissuefiled March 13, 1920. Serial No. 365,643.

To (1/ Z whom it may concern:

le it known that I, Cnannns HUGH Di'rrv, a citizen of the United States, residing at Chevy. Chase, in the county of Montgomery and State of Maryland, have invented new and useful improvements in method, construction and arrangement for.

seating and maintaining the insulating core within the metal shell of the plug to pre vent leakage of pressure.

The invention consists of. the novel construction and arrangement of the core-holding gland, and in the method for effecting the retention of the core within the same, and of effecting a gas-tight union between the gland and the metal shell and between the gland and the core,

The invention further consists of the construction which provides for rotation of both the upper and the lower gaskets unifornilyavith the insulating core and gland, and in the method of assembling the parts whereby rotation of the upper and lower packing gaskets uniformly with the insulating core and gland is assured.

In spark plugs wherein the insulating core is seated upon a packing gasket, and in which a rotatable gland is employed to press a packing gasket upon the insulating core, and to press the insulating core upon the lower packing gasket. a rotating move-- ment is imparted to the insulating core by the rotating gland, and the insulating core is thus caused to rotate on its lower pack ing gasket instead of being progressed or pressed straight into the gasket, while there also occurs a rotation of the gland onthe upper packing gasket. This rotation of the insulating core on its lower packing gasket, cuts and tears the said gasket so that an absolute gas-tight joint is prevented. In order to cause a packing-gasket or gaskets, such as are employed in spark plugs, to properly function and provide gas-tight joints, there should beno relative rotation between the insulating core and" the lower packing-gasket, nor between the gland and preferably the upper packing-gasket, but the insulatmg core should be pressed straight into the gasket so that the gasket will conform to the unevenness and irregularities in the shoulders of the insulating core. Experience has shown that these gaskets are scratched, scarred, torn and their utility impaired by rotating the insulating core thereon, or by rotating the gland on and relatively to the upper packing-gasket.

Referring to the accompanying drawing:

Figure 1 is a vertical sectional View of a spark plug constructed in accordance with this invention.

Fig. 2 is a fragmentary sectional View illustrating the manner of assembling the gland and core in the shell. as

Fig. 3, is an elevation of the gland and core after being assembled.

Fig. 4 is an elevation of the gland before entering the shell. I Fig. 5 is a bottom plan view of the shell, and

Fig. 6 is a vertical sectional view showing the shell, gland and core in an assembled position.

Like'numerals of reference indicate the same parts throughout the several figures, in which 1 indicates the spark plug comprising the threaded metal shell 2, gland 3,i n ting core 4:, central electrode 5- and groan... trode 6.

The core at has an enlarged contra 9 forming a flat shoulder 10 at its t a i5 shoulder 11 at its bone and is centrally apertured at 16 to rec ive the threaded central electrode 5. Referring to the gland 3 it will be that "the same is provided with a lie portion 22, a depending thin. tubular thimble portion 23 integral with the glan and an intermediate threaded portion for connection. with the internally threaded shell 52, while internally of the gland 3 at the beginning of the thin tubular portion 23, is a shoulder 25, the edge of said tubular portion being preferably rounded at W, flatted portion 22, tubular portion fill, and threaded portion. 24 being a unit.

The shell 2 is externally threaded at 3? for connection with a motor, and is prowe vided intermediatefits ends with'a downq l rin w waixlly lHCll11l annular shoulder 28, Elk shell apertures, to rsosivs tho core and gland 3 in the manner shown in Fig.1.

in assembling the plug, ails-J core Zillfl tral sleomroils semi" a proper pa-salon. 3,.-(l the core is placed in the gland 3, 2 gasket 35 Using prei" ablv provided between lillfi shoulder l of l s oo o anti limo shoulliiie 1 Molar portion 22% a yon-Q the inclined shoulder ll 01 ilio while a gasket is positioned on the shoulder i'l shown in lyisn is this position, the and and 001's are (l. in ins shell i}, the opem tion lasing iaoililaiol ii: ills parts are bold upsioi clown. The gland 3 is tln'saclecl into illi shell 2 so that the roumlecl' edge $28 of the. tubular extension 23 impinges iiiolined slioulclor as shown in FE liar ro 'zaiioii illG glanii 3 I; to progress inwardly of the shell she roumlml oflge 26 of the gland 8 i grailually spun inwardly, as shown ll ig. 3 03' the shoul-l-ei" Ulllliljilll entire end-poi'hioi of the slain tubular sxtsnsioii 23 spun over and upon the gasket 36 by the inclinscl shoulder and between said gasksi; 'afid the inclinscl shoulder of the shell As this spinning operation is be footed anl the inward progress of i lis being retarded by the h ills tubular POIlIiOIl 23, ills packingrslze' s anti 36 are 3' ss ll ills 611% portion of v 1; extension nuclei: the on the shoulder s" rotated on the slisll, sairil eilgi s ShOfllilQ'i. 521i thereon in such mananion is flfllffleil i38- Ill] "alt 5s i f :ly si'loot cl loo- {sen lll cl com 4 ml the gland ills This method 115,: the 211111,: ilii'eoi l v slioiikls; 28 of the shell :2

- ivantags filial) an absolufis 0ons iiim portion of $116: "rlaml moiliioml.

I miss ills gasiiss regularities of tho tw ll. into H s 11 the cutting,

slioulclsi' rotatingrtlie insulating core 01 the gland.

on or the packing-gasksts.

l'i' hat 1 claim nsw and desire to secure by Letters 1 a'l-eznt of the United States, is:

' plug comprising a metal shell fillleilflfii'ii connection with a motor, and having an iniernal bore and an. internal an salating core and suitable BlQClZFOLl S, a glaml for connection with said iiioll a tubular portion on said gland and ntegrazl therewith and an internal shoulder ,lorsiii, said tubular portion being adapted :6 receive saicl insulating core, the end of said. tubular portion being adapted to enthe said shoulder in said shell i0 spin saicl onii of said tubular portion under sail insulating core anal between the same and id shoulder in said. shelL upon rotation of said. gland in SELlQl shell.

spark plug comprising a IIlUl/iLL shell a bore ilisrsiii and. an internal shoals, 1', an insulating core having a central ring forming; an upper and a lower shoulder a and connect-ion with said shell and having an internal SllOlal lei: and an integral tubular portion to receive said insulating says, tho low er and of said tubulai portion being ailaptsd to engage saiil shoulvlsv in said shell to spin the same under said i'.;; illlil between i ho same and said shoulder in said shell, upon roiation of said mi in said shell.

spark plug;- compnsiug a metal shell having a shoulder therein, an insz-ilating having a" Bing; thereon, a gland having a shoulder therein aml an integral tubular poriion lo resolve said insulating core; said oubular poiiaion being adapted to engage and rotate on sai l sliouldin' in said shell to spin said tubular portion under said ring anal to grind a gas-tight joint between the spoil iriibulai portion and the shoulder in will slrsll A. spark 1 ving slwlililei" therein, a gland for. con- .iswioii ith said shell, an insulating core is be received by said gland, a tubular portion on and integral with said gland adapti saial shoulder in said shell and under saicl insulating com.

5. A spark plug omnprisinga shell, a -.insiilaiting ooio arm. a 9; nipiovidotl with a tubular portion imegral therewith adaptio m vs said insulating more, means "Within said shell to be 'sligaged by said 'tiiiiulais por' 'on of said. gland. to spin the inbular pomioii aiouml sar l insulating more upon the inwartl progression anrl rotation of g, within said shell.

6. spark "plug comprising a shell l1avshoulder islieicsin an insulaaing core ihe-i'smi forming an upper gland for connec- .grind a gas-tight joint between the shoulder in said shell and the tubular portion of the gland.

7. The herein described method of seating an insulating core in a spark plug shell which consists in inserting the insulating core in a threaded gland or bushing, in threading the gland or bushing into a spark plug shell to rotate the gland or bushing against a sl gulder in the spark plug shell to spin the said gland or bushing under the insulating core and between the same and the shoulder in the spark plug shell;

8. The herein described method of seating an insulating core in a spark plug shell, which consists in providing a spark plug shell with an internal shoulder and in providing a core-retaining gland with a thin tubular portion integral therewith, in inserting the insulating core within its re taining gland and in rotating the gland against the shoulder in the shell to spin the tubular portion of the land between the insulating core and the shoulder in the spark plug shel'.

9. The herein described method of ing an insulating core in a spark plug shell which consists in relatively rotating a threaded core retaining gland within and with relation to a spark plug shell to relatively progress the core retaining gland against a shoulder in the spark plug shell to spin the core retaining gland between the insulating core and the shoulder in the spark plug shell.

1b.. The herein described'method of seating an insulating core in a spark plug shell,

having an internal bore and an internal shoulder, an insulating core and suitable electrodes, a gland for connection with said shell, said gland including a tubular portion integral therewitlu an internal shoulder, said tubular portion being adapted to receive said insulating core, said' insulating core being provided with a shoulder adjacent the lower end of said tubular portion, a packing gasket on said shoulder on the insulating core, the said tubular portion of the gland having a spun portion over and upon said packinggasket, the whole arranged in such manner that upon rotation of the gland in seating the spun portion.

thereof on the shoulder in the said shell, the said packing gasket and insulating core rotate together and uniformly with the said gland, and the packing gasket is compressed between the insulating core and the spun portion of the gland. i

13. A spark plug including a metal shell having a bore therein and an internal shoulder, an insulating core having a central ring forming an upper and a lower shoulder, a

which consists in relatively progressing a".

threaded core-retaining gland inwardly of a spark plug shell and against a- Sl'l()lll(.ll"

therein to distort the said threaded core retaining gland and spin the gland between the insulating core and the spark plug shell.

11. The herein. described method of retaining an insulating core within a spark plug gland, which consists in relatively progressing a threaded core-retaining gland inwardly of a. shell and against a shoulder therein to distort the said threaded eori retaining gland and spin the gland between the insulating core and the shoulder in the shell.

153. it spark plug including a metal shell threaded for connection with a motor and gland for connection with said shell and having an internal shoulde' and a tubular portion integral with the gland to receive said insulating core, and a packing gasket on the said lower shoulder of the central ring, the lower end oi said tubular portion having a spun portion over and upon said packing gasket, whereby upon the seating of the gland and insulatiugcore on the shoulder in the shell by the rotation of said gland in saulshell, the said packing gasket and insulating core are rotated together and uniformly withthe said gland, and the said gasket is compressed between the insulating core and the spun portion oi the gland.

1.4. A spark plug including a metal shell.

having a shouldertherein, an insulating core havmg a ring thereon, a rotatable gland having a shoulder therein and a tubular portion to receive said insulating core,

and a gasket under. saidring, the tubular portion of said gland having .a spun portion under-and against said gasket and between the same and the said shoulder in the shell; whereby upon rotation otthe said gland as 'in seating the spun portion thereof on the,

shoulder in the shell, the said. gasket and in sulating core are rotated uniformly with the said gland, and the said gasket is compressed between the insulating core and the spun portion ot the gland.

15. A spark plug including a, metal shell having a shouldertherein, a gland haying threaded connection with said shell/an insulating core within said gland, said gland including a tubular portion integral therewith, and a packing gasket on said insulating core,- the said tubular portion of the gland haying a spun portion under and against said packing gasket and between the same and the said shoulder in the shell; whereby upon threading the said glan into the said shell and against the shoulder in the shell, the said gasket and insulating core are rotated uniformly with the said gland and the said gasket is compressed between the insulating core and the spun portion of the gland 16. A spans-plug including a shell, an insulating core, a gland harin tureaded connection with the shell and receiving said insulating core, and a packing gasket on said insulating core, the said gland including a spun per ton integral therewith, the said shell including means forming a seat for said spun portion, the said spun portion being disposed under and against said gasket and between the same and said means in said shell; whereof upon threading said gland in the shell to seat the said spun portion on the said means in the shell, the said gasket and insulating core are rotated together and uniformly with the said gland,

and the gasket is compressed between the insulating core and the spun portion ot the gland 17. A. spark plug comprising a shell hav ing a shouldeitherein. an insulating core having a ring thereon forming an upper and a lower shoulder, a gland for threaded connection with said shell and provided with an internal shoulder and including a, tubular portion to receive said insulating core, a parking gasket between, the shoulder in the said gland and the upper shoulder on said insulating core, said ,Q'ltli'ill harm-(ling a spun portion under the lower shouldei ot' the insulating core and between the sai e and the shoulder in the shell, said spun portion being a part of and ri'itatalile with the gland; whereby upon rotation of the gland and its spun portion to seat the spun portion on the shoulder in the shelhthe said packing gasket is compressed between the shoulder in the gland and the upper shoulder on the insulating core to form a' gastight union between the insulating core and. the gland.

18. A spark plug including a metal shell threaded'for connection with a motor and having an internal bore and an internal shoulder, an insulating core and suitable electrodes, a threaded gland for threaded connection with said'shell, said gland including a tubular portion integral therewith and having an internal shoulder, av packing gasket on said shoulder, said insulating core being within said tubular portion and against said packing gasket, the said tuhw lar portion including a spun portion. under the insulating core and, between and the shoulder in the shell; whereby noon tation of the gland in seating portion on the shoulder in the kiln/ll. -4-, said packing gasket and insulating core are laser, I j

rotated together and uniformly With said gland, and the said gasket is compressed between the insulating core and the internal shoulderiu the gland.

19; T he herein clescriceu method or retaining an insulating core in a, spark p ug gland, consisting in. inserting the insula ing core in. a threaded gland or bushing, in positioning a packing gasket on the insulating core and Within the gland, and in threading the seat the said gland or bushing on a shoulder in a ark plug shell, and to compress said packing gasket between the insulating core and that portion of the gland seated on the shoulder in the spark plug shell.

2). The herein described method of iretaining an insulating core in a thread d.

spark plug gland. consisting in positionil g a packing gasket in said threaded gland, in inserting the insulating core in said threaded gland and upon said packing gasket therein. and in tin-ceding said gland in l spark plng shell andupon a shoulder :hcreia to seat said gland on said shoulder and to compress the gasket between the threaded gland, and the insulating core.

'lhe herein described method of retaining an insulating core in a threaded spark plug gland, which comprises positioning an insulating core and a packing gasket within said threaded gland, and in'sp'inning ind seating the gland on a shoulder in a spark plug shell to compress the said packing gasket between the spun portion of the threaded glano. and the insulating core.

32. The herein described method of reaining an insulating core in threaded laud having an internal shoulder and a hin tubular portion integral with the gland, ncluding the inserting of an. insulating ore within the tubular portion of the gland,

in positioning a packing gasket on the in sulating core, andin seating the tubular portion of the gland on a shoulder in a spark vplug shell to compress the packing gasket between the il'isulating core and the portion oi the threaded gland seated on e shoulder in the spark plug shell.

A, spark plug including an internally threaded shell, 21 gland threaded for connection with said shell and including a thin depending tubular extension integral with the gland, a shouldered insulating core within said gland, a packing gasket on the shoulder of the insulating core, said tubular extension including a spun portion over and against the said packing; gasket for retaining the insulating core and packing gasket against relative rotation upon threading the gland into thesairl Qhell to seat the L It a gland threaded for connection with said gland into spark plug shell to' shell including thin tub-Illa integral Nil/l1 b shoulder, an insula'w gland and. ha

land ancl an 111g care Wi ving an upper and a, l 2: packing an *ulle com and a gland, a packing of the insulmb the shoulder 11]. the

pm lion over and against the packing gasket 10 on the lower shoulder of the insulating core, film Said gland @7116. its spun portion retaining the insulating care and its upper and its lnwer packing gasket against relative rotation upnn the seating 0f the spun poriion of the gland on the shoulder in the shell. In testimony whereof l: sdfix m%si ature.

- filial.

0n the lower should the 511111 tulvu sulasE-ing care,

lm' exbensian including a CHARLES HUGH 

